Would the Australian encryption laws impact Fastmail that much? AFAIK their emails were never encrypted at rest to begin with so someone with a warrant could always have gotten in.

The question is why you would ever expose your data to the control of lawmakers who make such laws if you're not Australian.

You should take a look at https://fastmail.blog/2018/09/10/access-and-assistance-bill/. They say it doesn’t affect their customers.

While that's true it's also because they don't use E2E. Which I guess makes any discussion about encryption backdoors rather pointless.

If you need E2E encryption, you shouldn't use email.

If you think I'm saying no one should still be using email (the collection of standards and protocols, that is) then you are correct.

If you're worried about E2E then I'm not sure what options you have other than maybe proton mail (and then only if both parties are using it) or GPG-encrypting messages, at which point host is irrelevant.

While the legislation introduced by the Australian government is certainly worrying and should never had been enacted, I've always operated under the assumption that if any government agency around the world really wants to get to my encrypted data or traffic, they'll likely be able to use/abuse some sort of loophole in their current processes and laws anyway.

Not if you are the only one holding the encryption keys to your content.

Email cannot really be secure, the recipient also has the copy, so holding encryption keys is meh?

They can secure their email as well?

If that's the case then why would the Australian government need to open the door even wider? The implication is that privacy laws pose inconveniences.